Variation in sensitivity of Western Australian isolates of Phytophthora cinnamomi to phosphitein vitro

Wilkinson, C.J., Shearer, B.L., Jackson, T.J. and Hardy, G.E.St.J. (2001) Variation in sensitivity of Western Australian isolates of Phytophthora cinnamomi to phosphitein vitro. Plant Pathology, 50 (1). pp. 83-89.

Abstract

Seventy-one Australian isolates of Phytophthora cinnamomi (68 from Western Australia) were tested for sensitivity to phosphite on Ribeiro's modified medium. Isolates formed a continuum in their response to phosphite, but could be divided into sensitive (9% of isolates), intermediate (82%) and tolerant (9%) groups. Sensitivity varied between isolates, with EC₅₀ values ranging from 4 to 148 μg phosphite mL^-1. Phytophthora cinnamomi A1 mating-type isolates were at the upper end of the range of tolerance shown by the A2 mating-type isolates.